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2001-08-11  Tim Waugh  

        * serial.c (get_pci_port): Deal with awkward Titan cards.

1998-08-26  Theodore Ts'o  

        * serial.c (rs_open): Correctly decrement the module in-use count

                on errors.

Thu Feb 19 14:24:08 1998  Theodore Ts'o  

        * tty_io.c (tty_name): Remove the non-reentrant (and non-SMP safe)

                version of tty_name, and rename the reentrant _tty_name

                function to be tty_name.

                (tty_open): Add a warning message stating callout devices

                are deprecated.

Mon Dec  1 08:24:15 1997  Theodore Ts'o  

        * tty_io.c (tty_get_baud_rate): Print a warning syslog if the

                tty->alt_speed kludge is used; this means the system is

                using the deprecated SPD_HI ioctls.

Mon Nov 24 10:37:49 1997  Theodore Ts'o  

        * serial.c, esp.c, rocket.c: Change drivers to take advantage of

                tty_get_baud_rate().

        * tty_io.c (tty_get_baud_rate): New function which computes the

                correct baud rate for the tty.  More factoring out of

                common code out of the serial driver to the high-level tty

                functions....

Sat Nov 22 07:53:36 1997  Theodore Ts'o  

        * serial.c, esp.c, rocket.c: Add tty->driver.break() routine, and

                allow high-level tty code to handle the break and soft

                carrier ioctls.

        * tty_ioctl.c (n_tty_ioctl): Support TIOCGSOFTCAR and

                TIOCSSOFTCAR, so that device drivers don't have to support

                it.

        * serial.c (autoconfig): Change 16750 test to hopefully eliminate

                false results by people with strange 16550As being

                detected as 16750s.  Hopefully 16750s will still be

                detected as 16750, and other weird UARTs won't get poorly

                autodetected.  If this doesn't work, I'll have to disable

                the auto identification for the 16750.

        * tty_io.c (tty_hangup): Now actually do the tty hangup

                processing during the timer processing, and disable

                interrupts while doing the hangup processing.  This avoids

                several nasty race conditions which happened when the

                hangup processing was done asynchronously.

                (tty_ioctl): Do break handling in the tty driver if

                driver's break function is supported.

                (tty_flip_buffer_push): New exported function which should

                be used by drivers to push characters in the flip buffer

                to the tty handler.  This may either be done using a task

                queue function for better CPU efficiency, or directly for

                low latency operation.

        * serial.c (rs_set_termios): Fix bug rs_set_termios when

                transitioning away from B0, submitted by Stanislav

                Voronyi.

Thu Jun 19 20:05:58 1997  Theodore Ts'o  

        * serial.c (begin_break, end_break, rs_ioctl): Applied patch

                to support BSD ioctls to set and clear the break

                condition explicitly.

        * console.c (scrup, scrdown, insert_line, delete_line): Applied

                fix suggested by Aaron Tiensivu to speed up block scrolls

                up and down.

        * n_tty.c (opost_block, write_chan): Added a modified "fast

                console" patch which processes a block of text via

                "cooking" efficiently.

Wed Jun 18 15:25:50 1997  Theodore Ts'o  

        * tty_io.c (init_dev, release_dev): Applied fix suggested by Bill

                Hawes to prevent race conditions in the tty code.

        * n_tty.c (n_tty_chars_in_buffer): Applied fix suggested by Bill

                Hawes so that n_tty_chars_in_buffer returns the correct

                value in the case when the tty is in cannonical mode.  (To

                avoid a pty deadlock with telnetd.)

Thu Feb 27 01:53:08 1997  Theodore Ts'o  

        * serial.c (change_speed): Add support for the termios flag

                CMSPAR, which allows the user to select stick parity.

                (i.e, if PARODD is set, the parity bit is always 1; if

                PARRODD is not set, then the parity bit is always 0).

Wed Feb 26 19:03:10 1997  Theodore Ts'o  

        * serial.c (cleanup_module): Fix memory leak when using the serial

                driver as a module; make sure tmp_buf gets freed!

Tue Feb 25 11:01:59 1997  Theodore Ts'o  

        * serial.c (set_modem_info): Add support for setting and clearing

                the OUT1 and OUT2 bits.  (For special case UART's, usually

                for half-duplex.)

                (autoconfig, change_speed): Fix TI 16750 support.

Sun Feb 16 00:14:43 1997  Theodore Ts'o  

        * tty_io.c (release_dev): Add sanity check to make sure there are

                no waiters on tty->read_wait or tty->write_wait.

        * serial.c (rs_init): Don't autoconfig a device if the I/O region

                is already reserved.

        * serial.c (serial_proc_info): Add support for /proc/serial.

Thu Feb 13 00:49:10 1997  Theodore Ts'o  

        * serial.c (receive_chars): When the UART repotrs an overrun

                condition, it does so with a valid character.  Changed to

                not throw away the valid character, but instead report the

                overrun after the valid character.

        * serial.c: Added new #ifdef's for some of the advanced serial

                driver features.  A minimal driver that only supports COM

                1/2/3/4 without sharing serial interrupts only takes 17k;

                the full driver takes 32k.

Wed Feb 12 14:50:44 1997  Theodore Ts'o  

        * vt.c:

        * pty.c:

        * tty_ioctl.c:

        * serial.c: Update routines to use the new 2.1 memory access

                routines.

Wed Dec  4 07:51:52 1996  Theodore Ts'o  

        * serial.c (change_speed): Use save_flags(); cli() and

                restore_flags() in order to ensure we don't accidentally

                turn on interrupts when starting up the port.

                (startup): Move the insertion of serial structure into the

                IRQ chain earlier into the startup processing.  Interrupts

                should be off this whole time, but we eventually will want

                to reduce this window.

Thu Nov 21 10:05:22 1996  Theodore Ts'o  

        * tty_ioctl.c (tty_wait_until_sent): Always check the driver

                wait_until_ready routine, even if there are no characters

                in the xmit buffer.  (There may be charactes in the device

                FIFO.)

                (n_tty_ioctl): Add new flag tty->flow_stopped which

                indicates whether the tty is stopped due to a request by

                the TCXONC ioctl (used by tcflow).  If so, don't let an

                incoming XOFF character restart the tty.  The tty can only

                be restarted by another TCXONC request.

        * tty_io.c (start_tty): Don't allow the tty to be restarted if

                tty->flow_stopped is true.

        * n_tty.c (n_tty_receive_char): If tty->flow_stopped is true, and

                IXANY is set, don't eat a character trying to restart the

                tty.

        * serial.c (startup): Remove need for MCR_noint from the

                async_struct structure.  Only turn on DTR and RTS if the

                baud rate is not zero.

                (change_speed): More accurately calculate the timeout

                value based on the word size.  Move responsibility of

                hangup when speed becomes B0 to rs_set_termios()

                (set_serial_info): When changing the UART type set the

                current xmit_fifo_size as well as the permanent

                xmit_fifo_size.

                (rs_ioctl): Fix TCSBRK (used by tcdrain) and TCSBRKP

                ioctls to return EINTR if interrupted by a signal.

                (rs_set_termios): If the baud rate changes to or from B0,

                this function is now responsible for setting or clearing

                DTR and RTS.  DTR and RTS are only be changed on the

                transition to or from the B0 state.

                (rs_close): Wait for the characters to drain based on

                info->timeout.  At low baud rates (50 bps), it may take a

                long time for the FIFO to completely drain out!

                (rs_wait_until_sent): Fixed timeout handling.  Now

                releases control to the scheduler, but checks frequently

                enough so that the function is sensitive enough to pass

                the timing requirements of the NIST-PCTS.

                (block_til_ready): When opening the device, don't turn on

                DTR and RTS if the baud rate is B0.

Thu Nov 14 00:06:09 1996  Theodore Ts'o  

        * serial.c (autoconfig): Fix autoconfiguration problems;

                info->flags wasn't getting initialized from the state

                structure.  Put in more paranoid test for the 16750.

Fri Nov  8 20:19:50 1996  Theodore Ts'o  

        * n_tty.c (n_tty_flush_buffer): Only call driver->unthrottle() if

                the tty was previous throttled.

                (n_tty_set_termios, write_chan): Add changes suggested by

                        Simon P. Allen to allow hardware cooking.

        * tty_ioctl.c (set_termios): If we get a signal while waiting for

                the tty to drain, return -EINTR.

        * serial.c (change_speed): Add support for CREAD, as required by

                POSIX.

Sat Nov  2 20:43:10 1996  Theodore Ts'o  

        * serial.c: Wholesale changes.  Added support for the Startech

                16650 and 16650V2 chips.  (WARNING: the new startech

                16650A may or may not work!)  Added support for the

                TI16750 (not yet tested).  Split async_struct into a

                transient part (async_struct) and a permanent part

                (serial_state) which contains the configuration

                information for the ports.  Added new driver routines

                wait_until_sent() and send_xchar() to help with POSIX

                compliance.  Added support for radio clocks which waggle

                the carrier detect line (CONFIG_HARD_PPS).

        * tty_ioctl.c (tty_wait_until_sent): Added call to new driver

                function tty->driver.wait_until_sent(), which returns when

                the tty's device xmit buffers are drained.  Needed for

                full POSIX compliance.

                (send_prio_char): New function, called by the ioctl's

                TCIOFF and TCION; uses the new driver call send_xchar(),

                which will send the XON or XOFF character at high priority

                (and even if tty output is stopped).

Wed Jun  5 18:52:04 1996  Theodore Ts'o  

        * pty.c (pty_close): When closing a pty, make sure packet mode is

                cleared.

Sun May 26 09:33:52 1996  Theodore Ts'o  

        * vesa_blank.c (set_vesa_blanking): Add missing verify_area() call.

        * selection.c (set_selection): Add missing verify_area() call.

        * tty_io.c (tty_ioctl): Add missing verify_area() calls.

        * serial.c (rs_ioctl): Add missing verify_area() calls.

                (rs_init): Allow initialization of serial driver

                configuration from a module.

        * random.c (extract_entropy): Add missing verify_area call.

                Don't limit number of characters returned to

                32,768. Extract entropy is now no longer a inlined

                function.

                (random_read): Check return value in case extract_entropy

                returns an error.

                (secure_tcp_sequence_number): New function which returns a

                secure TCP sequence number.  This is needed to prevent some

                nasty TCP hijacking attacks.

                (init_std_data): Initialize using gettimeofday() instead of

                struct timeval xtime.

                (fast_add_entropy_word, add_entropy_word): Rename the

                inline function add_entropy_word() to

                fast_add_entropy_word().  Make add_entropy_word() be the

                non-inlined function which is used in non-timing critical

                places, in order to save space.

                (initialize_benchmark, begin_benchmark, end_benchmark): New

                functions defined when RANDOM_BENCHMARK is defined.  They

                allow us to benchmark the speed of the

                add_timer_randomness() call.

                (int_ln, rotate_left): Add two new inline functions with

                i386 optimized asm instructions.  This speeds up the

                critical add_entropy_word() and add_timer_randomness()

                functions, which are called from interrupt handlers.

Tue May  7 22:51:11 1996    

        * random.c (add_timer_randomness): Limit the amount randomness

                that we estimate to 12 bits.  (An arbitrary amount).

                (extract_entropy): To make it harder to analyze the hash

                function, fold the hash function in half using XOR, and

                use the folded result as the value to emit to the user.

                Also, add timer randomness each pass through the

                exact_entropy call, to increase the amount of unknown

                values during the extraction process.

                (random_ioctl): Use IOR/IOW definitions to define the

                ioctl values used by the /dev/random driver.  Allow the

                old ioctl values to be used for backwards compatibility

                (for a limited amount of time).

Wed Apr 24 14:02:04 1996  Theodore Ts'o  

        * random.c (add_timer_randomness): Use 2nd derivative as well to

                better estimate entropy.

                (rand_initialize): Explicitly initialize all the pointers

                to NULL.  (Clearing pointers using memset isn't portable.)

                Initialize the random pool with OS-dependent data.

                (random_write): Add sanity checking to the arguments to

                random_write(), so that bad arguments won't cause a kernel

                SEGV.

                (random_read): Update the access time of the device inode

                when you return data to the user.

                (random_ioctl): Wake up the random_wait channel when there

                are only WAIT_INPUT_BITS available.  Add more paranoia

                checks to make sure entropy_count doesn't go beyond the

                bounds of (0, POOLSIZE).  Add a few missing verify_area

                checks.  Add support for the RNDCLEARPOOL ioctl, which

                zaps the random pool.

                (add_timer_randomness): Wake up the random_wait

                channel only when there are WAIT_INPUT_BITS available.

                (random_select): Allow a random refresh daemon process to

                select on /dev/random for writing; wake up the daemon when

                there are less than WAIT_OUTPUT_BITS bits of randomness

                available.

Tue Apr 23 22:56:07 1996    

        * tty_io.c (init_dev): Change return code when user attempts to

                open master pty which is already open from EAGAIN to EIO,

                to match with BSD expectations.  EIO is more correct

                anyway, since EAGAIN implies that retrying will be

                successful --- which it might be.... Eventually!!

        * pty.c (pty_open, pty_close): Fix wait loop so that we don't

                busy loop while waiting for the master side to open.

                Fix tty opening/closing logic.  TTY_SLAVE_CLOSED was

                renamed to TTY_OTHER_CLOSED, so that the name is more

                descriptive.  Also fixed code so that the tty flag

                actually works correctly now....

Mon Apr  1 10:22:01 1996    

        * serial.c (rs_close): Cleaned up modularization changes.

                Remove code which forced line discipline back to N_TTY

                this is done in the tty upper layers, and there's no

                reason to do it here.  (Making this change also

                removed the requirement that the serial module access

                the internal kernel symbol "ldiscs".)

        * tty_io.c (tty_init): Formally register a tty_driver entry for

                /dev/tty (device 4, 0) and /dev/console (device 5, 0).

                This guarantees that major device numbers 4 and 5 will be

                reserved for the tty subsystem (as they have to be because

                of /dev/tty and /dev/console).  Removed tty_regdev, as

                this interface is no longer necessary.

Sun Mar 17 20:42:47 GMT 1996 

        * serial.c : modularisation (changes in linux/fs/device.c allow

                kerneld to automatically load the serial module).

        * Makefile, Config.in : serial modularisation adds.

        * tty_io.c : tty_init_ctty used by to register "cua" driver just

                for the /dev/tty device (5,0).  Added tty_regdev.

        * serial.c (shutdown, rs_ioctl) : when port shuts down wakeup processes

          waiting on delta_msr_wait. The TIOCMIWAIT ioctl returns EIO

          if no change was done since the time of call.

Sat Mar 16 14:33:13 1996 

        * tty_io.c (disassociate_ctty): If disassociate_ctty is called by

                exit, do not perform an implicit vhangup on a pty.

Fri Feb  9 14:15:47 1996    

        * serial.c (block_til_ready): Fixed another race condition which

                happens if a hangup happens during the open.

Wed Jan 10 10:08:00 1996    

        * serial.c (block_til_ready): Remove race condition which happened

                if a hangup condition happened during the setup of the

                UART, before rs_open() called block_til_ready().  This

                caused the info->count counter to be erroneously

                decremented.

        * serial.c (startup, rs_open): Remove race condition that could

                cause a memory leak of one page.  (Fortunately, both race

                conditions were relatively rare in practice.)

Tue Dec  5 13:21:27 1995    

        * serial.c (check_modem_status, rs_ioctl): Support the new

                ioctl()'s TIOCGICOUNT, TIOCMIWAIT.  These allow an

                application program to wait on a modem serial register

                status bit change, and to find out how many changes have

                taken place for the MSR bits.

                (rs_write): Eliminate a race condition which is introduced

                if it is necessary to wait for the semaphore.

Sat Nov  4 17:14:45 1995    

        * tty_io.c (tty_init): Move registration of TTY_MAJOR and

                TTY_AUX_MAJOR to the end, so that /proc/devices looks

                prettier.

        * pty.c (pty_init): Use new major numbers for PTY master and slave

                devices.  This allow us to have more than 64 pty's.  We

                register the old pty devices for backwards compatibility.

                Note that a system should either be using the old pty

                devices or the new pty devices --- in general, it should

                try to use both, since they map into the same pty table.

                The old pty devices are strictly for backwards compatibility.

Wed Oct 11 12:45:24 1995    

        * tty_io.c (disassociate_ctty): If disassociate_ctty is called by

                exit, perform an implicit vhangup on the tty.

        * pty.c (pty_close): When the master pty is closed, send a hangup

                to the slave pty.

                (pty_open): Use the flag TTY_SLAVE_CLOSED to test to see

                if there are any open slave ptys, instead of using

                tty->link->count.  The old method got confused if there

                were processes that had hung-up file descriptors on the

                slave tty.

Tue May  2 00:53:25 1995    

        * tty_io.c (tty_set_ldisc): Wait until the output buffer is

                drained before closing the old line discipline --- needed

                in only one case: XON/XOFF processing.

        * n_tty.c (n_tty_close): Don't bother waiting until the output

                driver is closed; in general, the line discipline

                shouldn't care if the hardware is finished

                transmitting before the line discipline terminates.

        * tty_io.c (release_dev): Shutdown the line discipline after

                decrementing the tty count variable; but set the

                TTY_CLOSING flag so that we know that this tty structure

                isn't long for this world.

        * tty_io.c (init_dev): Add sanity code to check to see if

                TTY_CLOSING is set on a tty structure; if so, something

                bad has happened (probably a line discipline close blocked

                when it shouldn't have; so do a kernel printk and then

                return an error).

Wed Apr 26 10:23:44 1995  Theodore Y. Ts'o  

        * tty_io.c (release_dev): Try to shutdown the line discipline

                *before* decrementing the tty count variable; this removes

                a potential race condition which occurs when the line

                discipline close blocks, and another process then tries

                open the same serial port.

        * serial.c (rs_hangup): When hanging up, flush the output buffer

                before shutting down the UART.  Otherwise the line

                discipline close blocks waiting for the characters to get

                flushed, which never happens until the serial port gets reused.

Wed Apr 12 08:06:16 1995  Theodore Y. Ts'o  

        * serial.c (do_serial_hangup, do_softint, check_modem_status,

                rs_init):  Hangups are now scheduled via a separate tqueue

                structure in the async_struct structure, tqueue_hangup.

                This task is pushed on to the tq_schedule queue, so that

                it is processed synchronously by the scheduler.

Sat Feb 18 12:13:51 1995  Theodore Y. Ts'o  (tytso@rt-11)

        * tty_io.c (disassociate_ctty, tty_open, tty_ioctl): Clear

                current->tty_old_pgrp field when a session leader

                acquires a controlling tty, and after a session leader

                has disassociated from a controlling tty.

Fri Feb 17 09:34:09 1995  Theodore Y. Ts'o  (tytso@rt-11)

        * serial.c (rs_interrupt_single, rs_interrupt, rs_interrupt_multi):

                Change the number of passes made from 64 to be 256,

                configurable with the #define RS_ISR_PASS_LIMIT.

        * serial.c (rs_init, set_serial_info, get_serial_info, rs_close):

                Remove support for closing_wait2.  Instead, set

                tty->closing and rely on the line discipline to prevent

                echo wars.

        * n_tty.c (n_tty_receive_char):  IEXTEN does not need to be

                enabled in order for IXANY to be active.

                If tty->closing is set, then only process XON and XOFF

                characters.

Sun Feb 12 23:57:48 1995  Theodore Y. Ts'o  (tytso@rt-11)

        * serial.c (rs_timer): Change the interrupt poll time from 60

                seconds to 10 seconds, configurable with the #define

                RS_STROBE_TIME.

        * serial.c (rs_interrupt_multi, startup, shutdown, rs_ioctl,

                set_multiport_struct, get_multiport_struct): Add

                provisions for a new type of interrupt service routine,

                which better supports multiple serial ports on a single

                IRQ.

Sun Feb  5 19:35:11 1995  Theodore Y. Ts'o  (tytso@rt-11)

        * tty_ioctl.c (n_tty_ioctl, set_termios, tty_wait_until_sent):

        * serial.c (rs_ioctl, rs_close):

        * cyclades.c (cy_ioctl, cy_close):

        * n_tty.c (n_tty_close):  Rename wait_until_sent to

                tty_wait_until_sent, so that it's a better name to export

                in ksyms.c.

Sat Feb  4 23:36:20 1995  Theodore Y. Ts'o  (tytso@rt-11)

        * serial.c (rs_close): Added missing check for closing_wait2 being

                ASYNC_CLOSING_WAIT_NONE.

Thu Jan 26 09:02:49 1995  Theodore Y. Ts'o  (tytso@rt-11)

        * serial.c (rs_init, set_serial_info, get_serial_info,

                rs_close): Support close_wait in the serial driver.

                This is helpful for slow devices (like serial

                plotters) so that their outputs don't get flushed upon

                device close.  This has to be configurable because

                normally we don't want ports to be hung up for long

                periods of time during a close when they are not

                connected to a device, or the device is powered off.

                The default is to wait 30 seconds; in the case of a

                very slow device, the close_wait timeout should be

                lengthened.  If it is set to 0, the kernel will wait

                forever for all of the data to be transmitted.

Thu Jan 17 01:17:20 1995  Theodore Y. Ts'o  (tytso@rt-11)

        * serial.c (startup, change_speed, rs_init): Add support to detect

                the StarTech 16650 chip.  Treat it as a 16450 for now,

                because of its FIFO bugs.

Thu Jan  5 21:21:57 1995  

        * serial.c: (receive_char): Added counter to prevent infinite loop

                when a PCMCIA serial device is ejected.

Thu Dec 29 17:53:48 1994    

        * tty_io.c (check_tty_count): New procedure which checks

                tty->count to make sure that it matches with the number of

                open file descriptors which point at the structure.  If

                the number doesn't match, it prints a warning message.

Wed Dec 28 15:41:51 1994    

        * tty_io.c (do_tty_hangup, disassociate_ctty): At hangup time,

                save the tty's current foreground process group in the

                session leader's task structure.  When the session leader

                terminates, send a SIGHUP, SIGCONT to that process group.

                This is not required by POSIX, but it's not prohibited

                either, and it appears to be the least intrusive way

                to fix a problem that dialup servers have with

                orphaned process groups caused by modem hangups.

Thu Dec  8 14:52:11 1994    

        * serial.c (rs_ioctl): Don't allow most ioctl's if the serial port

                isn't initialized.

        * serial.c (rs_close): Don't clear the IER if the serial port

                isn't initialized.

        * serial.c (block_til_ready): Don't try to block on the dialin

                port if the serial port isn't initialized.

Wed Dec  7 10:48:30 1994  Si Park (si@wimpol.demon.co.uk)

        * tty_io.c (tty_register_driver): Fix bug when linking onto

                the tty_drivers list. We now test that there are elements

                already on the list before setting the back link from the

                first element to the new driver.

        * tty_io.c (tty_unregister_driver): Fix bug in unlinking the

                specified driver from the tty_drivers list. We were not

                setting the back link correctly. This used to result in

                a dangling back link pointer and cause panics on the next

                call to get_tty_driver().

Tue Nov 29 10:21:09 1994  Theodore Y. Ts'o  (tytso@rt-11)

        * tty_io.c (tty_unregister_driver): Fix bug in

                tty_unregister_driver where the pointer to the refcount is

                tested, instead of the refcount itself.  This caused

                tty_unregister_driver to always return EBUSY.

Sat Nov 26 11:59:24 1994  Theodore Y. Ts'o  (tytso@rt-11)

        * tty_io.c (tty_ioctl): Add support for the new ioctl

                TIOCTTYGSTRUCT, which allow a kernel debugging program

                direct read access to the tty and tty_driver structures.

Fri Nov 25 17:26:22 1994  Theodore Y. Ts'o  (tytso@rt-11)

        * serial.c (rs_set_termios): Don't wake up processes blocked in

                open when the CLOCAL flag changes, since a blocking

                open only samples the CLOCAL flag once when it blocks,

                and doesn't check it again.  (n.b.  FreeBSD has a

                different behavior for blocking opens; it's not clear

                whether Linux or FreeBSD's interpretation is correct.

                POSIX doesn't give clear guidance on this issue, so

                this may change in the future....)

        * serial.c (block_til_ready): Use the correct termios structure to

                check the CLOCAL flag.  If the cuaXX device is active,

                then check the saved termios for the ttySXX device.

                Otherwise, use the currently active termios structure.

Sun Nov  6 21:05:44 1994  Theodore Y. Ts'o  (tytso@rt-11)

        * serial.c (change_speed): Add support for direct access of

                57,600 and 115,200 bps.

Wed Nov  2 10:32:36 1994  Theodore Y. Ts'o  (tytso@rt-11)

        * n_tty.c (n_tty_receive_room): Only allow excess characters

                through if we are in ICANON mode *and* there are other no

                pending lines in the buffer.  Otherwise cut and paste over

                4k breaks.

Sat Oct 29 18:17:34 1994  Theodore Y. Ts'o  (tytso@rt-11)

        * serial.c (rs_ioctl, get_lsr_info): Added patch suggested by Arne

                Riiber so that user mode programs can tell when the

                transmitter shift register is empty.

Thu Oct 27 23:14:29 1994  Theodore Y. Ts'o  (tytso@rt-11)

        * tty_ioctl.c (wait_until_sent): Added debugging printk statements

                (under the #ifdef TTY_DEBUG_WAIT_UNTIL_SENT)

        * serial.c (rs_interrupt, rs_interrupt_single, receive_chars,

                change_speed, rs_close): rs_close now disables receiver

                interrupts when closing the serial port.  This allows the

                serial port to close quickly when Linux and a modem (or a

                mouse) are engaged in an echo war; when closing the serial

                port, we now first stop listening to incoming characters,

                and *then* wait for the transmit buffer to drain.

                In order to make this change, the info->read_status_mask

                is now used to control what bits of the line status

                register are looked at in the interrupt routine in all

                cases; previously it was only used in receive_chars to

                select a few of the status bits.

Mon Oct 24 23:36:21 1994  Theodore Y. Ts'o  (tytso@rt-11)

        * serial.c (rs_close): Add a timeout to the transmitter flush

                loop; this is just a sanity check in case we have flaky

                (or non-existent-but-configured-by-the-user) hardware.

Fri Oct 21 09:37:23 1994  Theodore Y. Ts'o  (tytso@rt-11)

        * tty_io.c (tty_fasync): When asynchronous I/O is enabled, if the

                process or process group has not be specified yet, set it

                to be the tty's process group, or if that is not yet set,

                to the current process's pid.

Thu Oct 20 23:17:28 1994  Theodore Y. Ts'o  (tytso@rt-11)

        * n_tty.c (n_tty_receive_room): If we are doing input

                canonicalization, let as many characters through as

                possible, so that the excess characters can be "beeped".

Tue Oct 18 10:02:43 1994  Theodore Y. Ts'o  (tytso@rt-11)

        * serial.c (rs_start): Removed an incorrect '!' that was

                preventing transmit interrupts from being re-enabled in

                rs_start().  Fortunately in most cases it would be

                re-enabled elsewhere, but this still should be fixed

                correctly.

Sun Oct  9 23:46:03 1994  Theodore Y. Ts'o  (tytso@rt-11)

        * tty_io.c (do_tty_hangup): If the tty driver flags

                TTY_DRIVER_RESET_TERMIOS is set, then reset the termios

                settings back to the driver's initial configuration.  This

                allows the termios settings to be reset even if a process

                has hung up file descriptors keeping a pty's termios from

                being freed and reset.

        * tty_io.c (release_dev): Fix memory leak.  The pty's other

                termios structure should also be freed.

        * serial.c (rs_close, shutdown): Change how we wait for the

                transmitter to completely drain before shutting down the

                serial port.  We now do it by scheduling in another

                process instead of busy looping with the interrupts turned

                on.  This may eliminate some race condition problems that

                some people seem to be reporting.

Sun Sep 25 14:18:14 1994  Theodore Y. Ts'o  (tytso@rt-11)

        * tty_io.c (release_dev): When freeing a tty make sure that both

                the tty and the o_tty (if present) aren't a process's

                controlling tty.  (Previously, we only checked the tty.)

        * serial.c (change_speed): Only enable the Modem Status

                Interrupt for a port if CLOCAL is not set or CRTSCTS

                is set.  If we're not checking the carrier detect and

                CTS line, there's no point in enabling the modem

                status interrupt.  This will save spurious interrupts

                from slowing down systems who have terminals that

                don't support either line.  (Of course, if you want

                only one of CD and CTS support, you will need a

                properly wired serial cable.)

Thu Sep 22 08:32:48 1994  Theodore Y. Ts'o  (tytso@rt-11)

        * tty_io.c (do_SAK): Return if tty is null.

        * tty_io.c (_tty_name): Return "NULL tty" if the passed in tty is

                NULL.

Sat Sep 17 13:19:25 1994  Theodore Y. Ts'o  (tytso@rt-11)

        * tty_ioctl.c (n_tty_ioctl): Fix TIOCGLCKTRMIOS and

                TIOCSLCKTRMIOS, which were totally broken.  Remove

                extra indirection from argument; it should be a struct

                termios *, not a struct termios **.

                &real_tty->termios_locked should have been

                real_tty->termios_locked.  This caused us to be

                reading and writing the termios_locked structure to

                random places in kernel memory.

        * tty_io.c (release_dev): Oops!  Forgot to delete a critical kfree

                of the locked_termios.  This leaves the locked_termios

                structure pointed at a freed object.

Fri Sep 16 08:13:25 1994  Theodore Y. Ts'o  (tytso@rt-11)

        * tty_io.c (tty_open): Don't check for an exclusive open until

                after the device specific open routine has been called.

                Otherwise, the serial device ref counting will be screwed

                up.

        * serial.c (rs_open, block_til_ready): Don't set termios structure

                until after block_til_ready has returned successfully.

                Modify block_til_ready to check the normal_termios

                structure directly, so it doesn't rely on termios being

                set before it's called.

Thu Sep 15 23:34:01 1994  Theodore Y. Ts'o  (tytso@rt-11)

        * serial.c (rs_close): Turn off interrupts during rs_close() to

                prevent a race condition with the hangup code (which

                runs during a software interrupt).

        * tty_io.c (release_dev): Don't free the locked_termios structure;

                its state must be retained across device opens.

        * tty_io.c (tty_unregister_driver): Added function to unregister a

                tty driver.  (For loadable device drivers.)